1. Field of the Invention
The present invention relates to a structure for supporting a thin-film magnetic head element, a thin-film magnetic head, and a method for manufacturing the supporting structure.
2. Description of Related Art
A magnetoresistive (MR) head comprises a supporting structure with an insulating film such as an alumina film deposited on a ceramic substrate. The ceramic substrate may be made of alumina titanium carbide. In an MR head of this type, a magnetic shield film is deposited on the insulating film. An MR element, a recording head element and so on are formed on the magnetic shield film. The magnetic shield film may be made of a soft magnetic material such as: a permalloy; a Co-based amorphous alloy like a Co--Nb--Zr or Co--Fe--B--Si alloy; and an FeAlSi alloy.
An MR head converts electric variations into magnetic ones, and vice versa, by taking advantage of magnetoresistance unlike an MIG head utilizing electromagnetic induction. Thus, an MR head can reproduce a large voltage without depending on a relative velocity between the head and a recording medium. In recent years, MR heads have been more and more often applied to hard disk drives (HDD) with a large capacity for computers to increase the recording density thereof.
A magnetic shield film for an MR head is required to increase the magnetic permeability thereof at radio frequencies. Specifically, the magnetic shield film needs to exhibit high magnetic permeability at frequencies within a range from about 100 MHz to about 300 MHz. To improve the magnetic permeability of the magnetic shield film, a technique of controlling and uniformizing the in-plane uniaxial magnetic anisotropy thereof over a wide area on a substrate should be developed.
If an FeAlSi alloy film such as a sendust film is used as a magnetic shield film and deposited directly on an insulating film like an alumina film, however, it is possible that the FeAlSi alloy film poorly adheres to the insulating film. In addition, it is difficult to control and uniformize the magnetic anisotropy of the FeAlSi alloy film over a wide area.